Sri Lanka captain Kumar Sangakkara elected to field after winning the toss against Bangladesh in a triangular one-day series match in Dhaka on Friday.
Sri Lanka made three changes from the side that beat India in the previous match, replacing Chanaka Welegedara, Suranga Lakmal and Muthumudalige Pushpakumara with Nuwan Kulasekara, Malinga Bandara and Mahela Jayawardene.
Bangladesh retained the side that lost to India by six wickets in the third match of the series on Thursday.
Each side will play four league matches before the top two advance to the final on January 13.
Bangladesh: Shakib Al Hasan (capt), Tamim Iqbal, Imrul Kayes, Mohammad Ashraful, Raqibul Hasan, Mushfiqur Rahim, Mohammad Mahmudullah, Naeem Islam, Abdur Razzak, Rubel Hossain, Syed Rasel.
Sri Lanka: Kumar Sangakkara (capt), Lahiru Thirimanne, Upul Tharanga, Mahela Jayawardene, Thilan Samaraweera, Thilina Kandamby, Thissara Perera, Suraj Randiv, Thilan Thushara, Nuwan Kulasekara, Malinga Bandara.
Umpires: Simon Taufel (AUS) and Shahid Saikat (BAN)
TV umpire: Enamul Haque (BAN)
Match referee: Andy Pycroft (ZIM)